Humanin vs MOTS-c
Reviewed by the BestHealingPeptides Editorial Team ·
Humanin and MOTS-c are both mitochondrial-derived peptides (MDPs) — small peptides encoded within mitochondrial DNA that act as retrograde signalling molecules between mitochondria and nucleus. They arise from distinct mtDNA loci (16S rRNA for humanin, 12S rRNA for MOTS-c), engage distinct pathways (Bax/Bak inhibition vs AMPK activation), and produce distinct phenotypes (cytoprotection vs metabolic regulation).
Humanin
A 24-amino-acid mitochondrial-derived peptide encoded within the mitochondrial 16S rRNA region (MTRNR2 gene), discovered by Hashimoto and colleagues in 2003 as a cytoprotective peptide against β-amyloid toxicity in neuronal culture. The first mitochondrial-derived peptide (MDP) with established bioactive function — foundational to the broader MDP field alongside MOTS-c. Circulating humanin concentrations decline with age and are reduced in Alzheimer's disease, type-2 diabetes, and other age-related conditions.
MOTS-c
A 16-amino-acid mitochondrial-derived peptide (MDP) encoded within the mitochondrial 12S rRNA region of the mitochondrial genome — the first MDP discovered with established metabolic-regulatory function. MOTS-c modulates AMPK signalling and folate cycle methylation, with pre-clinical evidence for effects on insulin sensitivity, exercise capacity, and skeletal-muscle glucose handling. Cross-listed in the metabolic and longevity clusters; not licensed in any jurisdiction.
| Aspect | Humanin | MOTS-c |
|---|---|---|
| mtDNA origin | 16S rRNA (MT-RNR2) | 12S rRNA (MT-RNR1) |
| Length | 24 amino acids | 16 amino acids |
| Discovery year and lab | 2001, Hashimoto (Tokyo) | 2015, Cohen (USC) |
| Principal mechanism | Bax/Bak inhibition; STAT3 signalling | AMPK activation; nuclear translocation |
| Principal phenotype | Cytoprotection, neuroprotection | Metabolic regulation, exercise endurance |
| Alzheimer-disease relevance | Discovery context; extensive research | Limited relevance |
| Metabolic-syndrome relevance | Limited relevance | Central research application |
| WADA status (2025) | Not listed | Prohibited (S2) |
Mitochondrial origins
Humanin is a 24-amino-acid peptide encoded within the mitochondrial 16S ribosomal RNA gene (MT-RNR2), discovered by Yuichi Hashimoto's laboratory in 2001 through screening for factors protecting neuronal cells from Alzheimer-disease-related toxicity. MOTS-c is a 16-amino-acid peptide encoded within the mitochondrial 12S ribosomal RNA gene (MT-RNR1), discovered by Pinchas Cohen's laboratory in 2015 through bioinformatic mining of small open reading frames within mitochondrial DNA. Both are mitochondrial-derived peptides (MDPs) — a class of endogenous peptides whose retrograde signalling function was established by these discoveries and has expanded to include additional MDPs (SHLPs, gau, humanin variants). Both peptides are translated from mitochondrial mRNAs, though whether by mitochondrial or cytoplasmic ribosomes remains debated.
Distinct downstream mechanisms
Humanin's principal characterised mechanism is direct binding and inhibition of pro-apoptotic Bcl-2 family members Bax and Bak, preventing their oligomerisation on the mitochondrial outer membrane and preserving mitochondrial membrane integrity against apoptotic stimuli. Humanin additionally engages a putative extracellular receptor complex (FPRL1, gp130/CNTFR/WSX-1) mediating cytoprotective STAT3 signalling. MOTS-c's principal characterised mechanism is AMPK activation through folate/AICAR-cycle intermediates, producing metabolic-regulator effects including enhanced glucose uptake, increased fatty-acid oxidation, and improved insulin sensitivity. MOTS-c additionally translocates to the nucleus and modulates stress-responsive nuclear transcription factors including NFE2L2 (Nrf2).
Phenotypic effects and research applications
Humanin research has concentrated on cytoprotective and neuroprotective applications: Alzheimer disease (the discovery context), ischaemic injury, chemotherapy toxicity, and various apoptotic-stress contexts. Effect sizes in pre-clinical models are typically modest but reproducible. MOTS-c research has concentrated on metabolic and exercise contexts: insulin sensitivity, obesity, type-2 diabetes, exercise-endurance enhancement (MOTS-c has been shown to increase running distance in rodents and is a WADA-listed prohibited substance for this reason), and age-related metabolic decline. The two peptides thus map onto distinct clinical-application spaces despite sharing the mitochondrial-origin classification.
Regulatory and anti-doping status
Neither humanin nor MOTS-c has achieved marketing authorisation in any jurisdiction; both remain research compounds. MOTS-c was added to the WADA Prohibited List (category S2, Peptide Hormones, Growth Factors, Related Substances and Mimetics) after publication of the exercise-endurance effects — its metabolic and endurance-enhancement pharmacology places it within the anti-doping framework. Humanin is not currently on the WADA Prohibited List — its cytoprotective mechanism does not fall within any current WADA category. Both are available from research-chemical suppliers for legitimate laboratory research; MHRA has jurisdiction over supply for human use for both compounds under the Human Medicines Regulations 2012.
Choosing between them (research context)
For research on mitochondrial-nuclear retrograde signalling as a general phenomenon, either compound is a valid probe of the MDP class. For cytoprotective and apoptosis-related research (neurodegeneration, ischaemic injury, chemotherapy toxicity), humanin is the appropriate tool. For metabolic and exercise-physiology research (insulin sensitivity, AMPK activation, endurance enhancement), MOTS-c is the appropriate tool. The two peptides are largely complementary rather than substitutable — the shared MDP classification obscures fundamentally distinct downstream pharmacology. Both are of particular interest to the longevity research field given the age-related decline in mitochondrial function and the retrograde-signalling framework's implications for cellular aging.
Verdict
Humanin and MOTS-c are both mitochondrial-derived peptides but pharmacologically distinct — humanin acts as a cytoprotective factor through Bax/Bak inhibition; MOTS-c acts as a metabolic regulator through AMPK activation. Choose humanin for cytoprotective and neuroprotective research; choose MOTS-c for metabolic and exercise-physiology research. MOTS-c's WADA-prohibited status is relevant for any research involving athletes.
Where to source research peptides for laboratory research
The following UK-based suppliers stock research-grade, lyophilised peptides for in-vitro and pre-clinical work. Purity and provenance vary; always request a Certificate of Analysis (CoA) and confirm cold-chain storage on arrival. None of the products linked below are approved for human use.
- PeptideAuthority.co.uk
UK-based research peptide supplier with batch certificates of analysis and >99% purity testing.
- PeptideBarn.co.uk
Wide catalogue of research-grade lyophilised peptides shipped from the UK, including bulk vials.